Project Summary Adenosine deaminases that act on RNA (ADARs) are enzymes that convert (?edit?) adenosines (A) into inosines (I) within RNA. As inosine is recognized as guanosine by the translation machinery, splicing factors, and other RNA binding molecules, A-to-I editing events can alter the coding potential of mRNA, RNA splicing and miRNA/siRNA mediated gene silencing. RNA editing is essential for proper neuronal function with aberrant editing associated with numerous neuropathological diseases and glioma malignancy. Organisms deficient in editing have numerous biological consequences including altered immune responses, altered neurological behavior, and altered lifespan. Understanding the substrates and mechanisms by which RNA editing affects biological functions such as these will be key to developing therapeutics capable of restoring proper function in disease states. The proposed studies will determine the RNA editome of neural cells as well as the biological consequences of editing specific transcripts. My central hypothesis is that tissue specific editing of neuronally expressed transcripts regulates expression of genes responsible for proper neurological behavior. To address this hypothesis the following aims have been proposed: Specific Aim 1: To determine the effect of A-to-I editing on the neuronal transcriptome. Rationale: Thus far, RNA editing studies in C. elegans have utilized whole worm extracts; however ADARs as well as their editing targets are differentially expressed in tissues. Specific Aim 2: To assess the biological consequences of editing within neural cells. Rationale: Though defects in chemotaxis in editing deficient C. elegans was identified over a decade ago, studies have not been able to identify the edited transcripts responsible nor the mechanisms by which editing alters chemotaxis behavior. The proposed studies will provide a rationale for therapeutic discovery leading to improved treatments for neuropathological diseases and cancer. The planned approach will be the first of its kind in the RNA editing field and spans from developing novel methodology for cell-type specific target identification to organismal behavior; thus, significantly advancing our understanding of the cellular mechanisms that regulate RNA editing. Furthermore, the completion of these studies will provide me with the skills necessary for establishing my career as an independent investigator.